Adolescents are chronically sleep-deprived with 97% of 12th graders getting insufficient sleep. Unfortunately, sleep is one of several areas of health where ethnic minorities suffer disparities. Sleep has profound influences on adolescent socioemotional and physical health and development. Moreover, research finds that sleep and health share a link to racial/ethnic discrimination. Integrating these areas of research, the proposed study is the first to explore the associations between discrimination, sleep, and health in a unified and longitudinal approach. The study explores sleep disturbance as an explanatory physiological mechanism through which racial/ethnic discrimination leads to compromised health in the short and longer term. The 2-year study includes Asian/Asian American (A/AA) adolescents starting in the 9th grade. Despite reporting rates of discrimination comparable to, and even higher than, other minorities A/AA youth have been neglected in the research on discrimination. Taking a biopsychosocial approach, the study explores the biological (i.e., sleep), psychological (i.e., racial/ethnic identity), social (i.e., racial/ethnic discrimination) pathways to adolescent health. Through the innovative combination of sleep actigraphy, daily surveys, and tri-annual reports of health, the study will make significant contributions to the science of social-biomedical influences on development. This unique methodological approach affords the ability to explore concurrent (i.e., daily-level) as well as longitudinal (i.e., year-over-year) analyses, providing a cutting-edge approach to exploring the temporal linkages in the development of disparities. The proposed study is guided by the following study aims: Aim 1: To explore the unique daily-level effects of racial/ethnic discrimination on sleep disturbance and health, adjusting for the effects of general stress. Aim 2: To investigate the hypothesis that daily-level sleep disturbance partially mediates the negative effect of daily racial/ethnic discrimination on health. Aim 3: To investigate the hypothesis that racial/ethnic identity moderates the effect of daily level racial/ethnic discrimination on sleep disturbance. Aim 4: To investigate the short- and longer-term effects of daily racial/ethnic discrimination and sleep disturbance on health over time. The proposed study adds a sample of A/AA adolescents to an on-going study of discrimination and sleep among African American and Latino youth. Consistent with ecosocial theory's construct of embodiment, the study will contribute to the science of health disparities by identifying the physiological pathway through which the social experiences of discrimination result in health disparities. The study relates to the NIH's mission by exploring the biopsychosocial mechanisms underlying the development of health disparities.